Grommet

Abstract

A grommet having a sealing lip (4), the sealing lip (4) extending about a longitudinal axis extending in an axial direction (A), the grommet having a spring section (10) configured to allow the sealing lip (4) to be compressible.

Description

[Technical Field]

[0001] The present invention relates to grommets, and more particularly to grommets used to route cables, lines or conduits through walls in a sealed manner. [Background technology]

[0002] Grommets are used in a variety of ways. Regardless of the specific application, they are always used to form a seal between two components and close or cover a gap that occurs between the two components. For example, in a vehicle, a cable is routed from the engine compartment to the dashboard inside the vehicle. The engine compartment is separated from the interior of the vehicle by a wall, and the cable is routed through this wall. For this purpose, a hole is made in the wall through which the cable can be routed. A grommet is then inserted into the hole to seal, and the grommet has a penetration through which the cable can be inserted. In this way, the cable does not come into direct contact with the wall, and the grommet fills the space between the pipe and the wall, sealing off two spaces on two opposite sides of the wall from each other.

[0003] In general, and particularly in the automotive sector, grommets must meet particularly high requirements in terms of leak-tightness against the passage of media, e.g., fluids or gases, and / or in terms of leak-tightness against sound, as well as always high mechanical requirements and requirements on the dimensions of the grommet due to installation space limitations, which requirements sometimes even lead to conflicting objectives in the design of the grommet. Summary of the Invention [Problem to be solved by the invention]

[0004] Against this background, it is an object of the present invention to provide an improved grommet, in particular one which forms a seal as good as possible against the passage of media and / or sound, withstands mechanical loads as well as possible, and takes up as little installation space as possible. [Means for solving the problem]

[0005] This problem is solved according to the invention by a grommet with the features according to claim 1. Advantageous designs, further developments and variations are the subject of the dependent claims.

[0006] The core idea of ​​the present invention is to design a grommet with a special sealing lip, in particular to meet the aforementioned requirements, where this sealing lip, in particular its shape and in particular its cross section, is designed in such a way that the sealing lip can be compressed in a specific, particularly advantageous way during assembly and, if necessary, also when subjected to subsequent mechanical loads, i.e. in particular so that the best possible sealing is still achieved, but with high mechanical flexibility and in a particularly small installation space on the mounting surface.

[0007] The grommet described herein has a sealing lip. The sealing lip is used to establish a sealing contact with an attachment surface, e.g., a side surface of a wall. The wall is, for example, a metal plate. The sealing lip preferably extends in an axial direction and annularly around a longitudinal axis perpendicular to the radial direction. According to the invention, the sealing lip has a spring section configured so that the sealing lip is compressible (i.e., can be compressed), especially during assembly, i.e., installation, of the grommet in or on the wall. Due to the spring section, the sealing lip is also referred to as a "spring sealing lip." Due to the spring section, the sealing lip is not designed as a simple ramp, but has a more complex shape.

[0008] The term "compressible" is understood to mean in particular "deformable by a pressing movement", "crushable", "squishable" or "foldable". The sealing lip is therefore designed to compress or crush itself when subjected to a mechanical load, in particular in the axial direction, and in particular during assembly. Conversely, the sealing lip or at least the spring section is preferably elastic, so that when the load decreases, the sealing lip is again automatically decompressed, preferably by the spring action of the spring section. The sealing lip is thus again deployed, expanded or decompressed.

[0009] The sealing lip is preferably conical or bell-shaped, particularly to a first approximation. Preferably, the sealing lip is rotationally symmetrical about the longitudinal axis. The grommet preferably has an inner body to which the sealing lip is connected, particularly radially outward, so that the sealing lip completely surrounds the inner body. In a preferred embodiment, the inner body serves to perform additional functions of the grommet other than sealing, for example, for the sealed retention of cables, lines or conduits by means of sockets or holes as part of the inner body. The inner body can have any number of sockets or holes, for example one, two or more. However, the presence and exact design of the inner body, whether it comprises sockets or holes, is not important in this example.

[0010] The grommet, and in particular its sealing lip, has a compressed, i.e., loaded, state and a non-compressed, i.e., unloaded, state. During assembly of the grommet, the grommet is always compressed, and preferably remains compressed in the assembled state, so that the sealing lip is permanently pressed against the mounting surface and thus provides a sealing effect. In this way, the sealing lip is, so to speak, pretensioned by the spring section in the assembled state.

[0011] The spring sections are arranged in particular circumferentially and extend annularly around the longitudinal axis, in particular around the inner body. The spring sections advantageously perform a spring function in particular in the axial direction, whereby the sealing lip can be compressed at least in the axial direction. The spring sections are therefore designed in an overall spring-like manner and suitably act in a spring-like manner, in particular when viewed in a cross section along the longitudinal axis. Said cross section along the longitudinal axis is spanned by the radial direction on the one hand and the axial direction on the other hand and originates from a cross-sectional plane in which the longitudinal axis lies. Insofar as merely a cross section is referred to below, a cross section along the longitudinal axis is meant, unless the respective context indicates otherwise.

[0012] The present invention is based, inter alia, on the observation that a grommet can, in principle, be designed with a circumferential, inclined sealing lip that protrudes from the inner body of the grommet at a specific angle and sealingly rests against the mounting surface. When subjected to mechanical loads, particularly in the axial direction during assembly, the sealing lip is spread or diverged, opening further (typically at a larger angle relative to the inner body), thereby achieving a sealing effect. The actual inclined shape of the sealing lip is largely maintained; only the angle of the sealing lip is different. However, this significantly increases the diameter of the grommet and occupies a corresponding amount of installation space. The same applies to axial mechanical loads in the assembled state. Additionally, such grommets may not be able to adequately absorb radial mechanical loads, i.e., perpendicular to the axial direction, and in such cases risk lifting off the mounting surface and losing their sealing effect.

[0013] In contrast to this, the spring sections described herein are advantageously configured to allow compression of the sealing lip when mechanical load is applied to the sealing lip in a manner that does not require additional installation space on the mounting surface. Instead, the spring sections are compressed, particularly in the axial direction, so that the sealing lip on the mounting surface absorbs the mechanical load without being expanded, at least not significantly.

[0014] The grommet may be, for example, a dash panel grommet for sealing the routing of cables, lines, or conduits from the engine compartment of a vehicle to the dash panel inside the vehicle, however, the invention is not limited to such applications and the concepts of the present invention may be used with any grommet.

[0015] In a preferred embodiment, the grommet includes a second sealing lip or counter-sealing lip, which is positioned opposite the wall such that, in the assembled (i.e., attached) state, the wall is sandwiched between the two sealing lips, thereby forming a two-sided seal against the wall. However, the presence and exact design of the second sealing lip are not relevant here. The second sealing lip may be a simple tapered sealing lip, but may also advantageously be configured as a spring sealing lip as described herein, so that the grommet has two spring sealing lips. In a preferred embodiment, the second sealing lip has a diameter larger than that of the spring sealing lip, although the second sealing lip may have other dimensions. Preferably, the second sealing lip is made of the same material as the spring sealing lip, and both sealing lips are manufactured in one piece, i.e., monolithically.

[0016] Preferably, the sealing lip comprises an end section that is attached to the spring section and that, after installation, is in direct contact with the mounting surface. As already indicated, the grommet preferably has an inner body to which the sealing lip is connected radially outward. More preferably, the spring section pivotally connects the inner body to the end section. In particular, the spring section is collapsed in compression and therefore acts in particular as a link or hinge that, in particular as a whole, preferably bulges radially outward.

[0017] It is advantageous for the sealing lip to be rounded at its end, and in particular for the end section to be rounded to facilitate contact with the mounting surface. Preferably, the end section is rounded so that when mounted on the mounting surface, the sealing lip undergoes a radial rolling motion, which deforms the spring section and compresses the sealing lip axially. In other words, during mounting, the spring section is tilted and deflected radially, resulting in deformation (i.e., compression). As a result, the sealing lip is compressed axially. Alternatively, or additionally, with the same effect, the sealing lip is rounded at its end so that it slides, i.e., performs a sliding motion, on the mounting surface when subjected to a mechanical load, but advantageously does not lose its sealing effect, since the end section continues to be pressed against the mounting surface by the preloaded spring section. Preferably, the rolling and / or sliding motion of the sealing lip, in particular its end section, is directed radially inward, thereby reducing the installation space on the mounting surface.

[0018] In a preferred embodiment, the end section, when viewed in cross section, has an outward-facing (i.e., toward the outside and toward the mounting surface) surface that is rounded or convex, and an inward-facing (i.e., toward the longitudinal axis and the inside of the grommet) surface that is flat or concave, but may also be convex or rounded. Upon installation, the outward-facing surface engages the mounting surface and rolls or slides across said mounting surface upon compression, causing the end section to roll and / or slide inward and the inward-facing section to pivot away from the mounting surface (similar to a shoveling action).

[0019] In a preferred embodiment, the end sections are already rotated inward in the uncompressed state and, in particular, are rotated further inward upon compression. The term "rotated inward" is understood to mean that the end sections are inclined inward relative to the mounting surface, in particular that, when viewed in cross section, the radius of the sealing lip along the end section decreases towards the mounting surface. In this way, the end sections are, so to speak, pre-rotated, which supports their inward movement.

[0020] The sealing lip is preferably rounded by having a spherical or drop-shaped shape at its end when viewed in cross section along the longitudinal axis. Due to the rounded design, when a load is applied, the end section rolls and / or slides on the mounting surface, which drives the spring sections radially and thus bulges, in particular, the spring sections are pulled apart.

[0021] A particularly preferred design is one in which the spring section is configured such that in the uncompressed (i.e., unloaded) state, the sealing lip is expanded (i.e., flared) in the axial direction, in particular like a cylinder, a cone, or a funnel, and in the compressed (i.e., loaded) state, it bulges radially, preferably outward, thus perpendicular to the axial direction. More specifically: the spring section, i.e., at least a part or a segment of the spring section, assumes a curved shape when loaded. The spring section preferably does not bulge in the uncompressed state and is preferably straight. The spring effect is therefore achieved precisely by the fact that, under load, the spring section bulges radially, thereby compressing the sealing lip in the axial direction. This bulge is preferably achieved by forming a bulge from a straight configuration or by enlarging an already existing bulge, i.e., by reducing the radius of curvature. This has the particular advantage that the sealing lip is configured such that the end section does not expand under load, and therefore does not require more installation space on the mounting surface. Instead, the spring sections are arched such that the end sections either remain in a fixed position on the mounting surface or move inwardly on the mounting surface, particularly towards the inner body, thereby at least maintaining or reducing the required installation space on the mounting surface.

[0022] The terms "funnel-shaped" and "bell-shaped" generally refer to the oblique path and orientation of the sealing lip relative to the longitudinal axis, resulting in the sealing lip assuming an overall funnel- or bell-shaped shape as it passes around the longitudinal axis. In other words, the sealing lip extends at an angle relative to the longitudinal axis, preferably in the range of 2° to 30° in the uncompressed state. However, this does not imply that the sealing lip itself has a thickness that varies in cross section to achieve the funnel or bell shape. Indeed, preferred embodiments involve the sealing lip having an inner wall generally facing toward the longitudinal axis and an outer wall generally facing the opposite direction. When viewed in cross section, the inner wall preferably has a contour that follows the contour of the outer wall. The sealing lip has a thickness, measured radially in the uncompressed state. The general material strength (i.e., the thickness measured perpendicular to the inner and / or outer wall) preferably does not change substantially when transitioning from the uncompressed state to the compressed state or vice versa.

[0023] The spring sections may be radially bulging outward (and thus convex in compression) or inward (and thus concave in compression). An outward bulge (i.e., convex curvature) is preferred. In other words, in preferred embodiments, the spring sections are configured to bulge outward when the sealing lip is attached, and thus generally when compressed. In particular, the spring sections are configured to bulge outward so that the volume inside the grommet is maintained or increased. This volume is defined as the volume enclosed between the grommet and the mounting surface. This has the advantage that a larger volume is available inside the grommet than in the absence or inward bulge case, resulting in improved acoustic properties of the grommet, particularly a better sound seal.

[0024] The curved shape is such that the inner and outer walls of the spring section curve in the same direction. In other words, the spring section bulges in only one direction and therefore, so to speak, folds. This is the opposite of a squeezed state, such as may be found in mostly soft materials such as foam or the like. Such squeezing preferably does not occur, or at least is not the primary mechanism for compression of the sealing lip. Instead, the spring section folds in such a way that a bulge occurs. In other words again, the inner and outer walls of the spring section move in the same direction (both radially outward or both radially inward) upon compression.

[0025] Preferably, the spring section is spring-like and has a plurality (i.e., at least two) segments (also called joints) that are connected to one another so that the spring section as a whole is articulated or hinged. The spring section preferably has two, three, or four segments, although other numbers are generally suitable depending on the application. One of the segments is the first segment, which is connected to the inner body. The other segment is the second segment, which is connected to the first segment. The second segment may be the last segment that contacts the mounting surface, or may be connected to a third segment or end section, as already mentioned, thereby connecting the first and third segments or end sections. Additional segments may be added as needed. In particular, two segments may be pivotally connected to one another, thereby enabling the aforementioned bulging of the spring section. Preferably, the bulging is achieved primarily by the rotation of the segments (i.e., their relative movement with respect to one another) and less by deformation of the individual segments themselves. In a preferred embodiment, at least two (preferably all) of the segments are pivotally connected to one another at a connection point (or fulcrum) such that a bend, crease, step, shoulder, notch, groove, etc. is formed at said connection point to facilitate pivoting. The bend, crease, notch, groove, etc. preferably extends annularly around the longitudinal axis. Alternatively or additionally, at least two of the segments are pivotally connected to one another at the connection point such that the spring section has a reduced thickness, measured radially, at said connection point to facilitate pivoting. In other words, in a preferred embodiment, the thickness of the spring section is reduced at the connection point compared to the thickness of the remainder of the segment.Such a reduction in thickness may be achieved, for example, by a tapered section at or around the connection point, such as a groove or notch, or by a bend, fold, step or shoulder, which is preferably configured such that the contour on the inner wall is displaced or offset axially and relative to the contour of the outer wall, such that a staggered arrangement is achieved in which the inner portion of the bend, fold, step or shoulder on the inner wall is shifted axially and relative to the outer portion of said bend, fold, step or shoulder on the outer wall.

[0026] In an advantageous embodiment, the spring sections, at least in the uncompressed state, have a stepped shape when viewed in cross section along the longitudinal axis. In the uncompressed state, if multiple steps are present, the steps preferably point in the same direction. In the compressed state, the segments preferably collapse into a serpentine shape or into a generally zigzag path, so that the segments alternately point in opposite directions, as already mentioned above, or alternatively bulge inwards or outwards together.

[0027] In an advantageous embodiment, the spring section has a serpentine shape, i.e., a serpentine shape, when viewed in cross section along the longitudinal axis, at least in the uncompressed state. In particular, each segment of the spring section forms a single bend. The bends are arranged so that the curvature direction alternates. In the compressed state, the segments preferably collapse so that the serpentine shape is radially stretched and axially compressed. In this way, each bend deforms radially inward or outward, so that the serpentine shape is generally maintained. Alternatively, as already mentioned in connection with the step, all bends bulge inward or outward, thereby eliminating the serpentine shape, so to speak.

[0028] In a particularly practical embodiment, the sealing lip comprises an end section configured as a massive section. The massive section is preferably configured so that, while the spring section deforms, it does not deform, but merely displaces as a result of deforming the spring section. To achieve this according to a preferred embodiment, the massive section is thicker than the spring section when measured in the radial direction. The sealing lip is thus thicker at the end, and the massive section thus has a greater thickness than the spring section, the thickness being measured in the cross-section and in the radial direction, i.e., perpendicular to the longitudinal axis. Preferably, the thickness is increased at least on the outer wall of the sealing lip, more preferably by a convex contour, so that the rounded end section is formed as described above, while at the same time the thickness at the end section is increased to obtain the massive section. In particular, the term "massive" is understood to refer to an increased thickness and / or volume of the massive section compared to the spring section. In a preferred embodiment, this also results in the massive section being heavier (i.e., having a greater mass) than the spring section, although this does not necessarily have to be the case. For example, in another preferred embodiment, the massive section is made from a material that is less dense than the material of the spring section, thereby achieving a massive section that is thicker and preferably more voluminous than the spring section, but not necessarily heavier. Preferably, the end of the spring section is the end that is furthest from the longitudinal axis, at least in the uncompressed state. If no massive section is attached to the end of the spring section, said end is preferably a free end.

[0029] The massive section is, as already mentioned above, a particularly preferred embodiment of the end section of the sealing lip. The massive section has a greater thickness than the spring section. Advantageously, the massive section is spherical or tear-shaped in cross section along the longitudinal axis, so that the sealing lip has an overall rounded end.

[0030] In particular when configured as a solid section, the end section together with the spring section forms a solid-spring system having advantageous mechanical properties.

[0031] Because the massive section is thicker than the spring section, under load, the spring section primarily deforms, especially compresses, while the massive section does not deform significantly, maintaining the grommet's sealing effect. In accordance with the different functions of the two sections (the massive section and the spring section) in the deformation of the sealing lip, the spring section is also referred to as the "first deformation zone" and the massive section as the "second deformation zone." While the massive section does not necessarily deform itself, it significantly influences the deformation of the spring section. In particular, this design prioritizes the axial deformation of the sealing lip over the radial deformation, advantageously limiting radial deformation and, therefore, radial protrusion, thereby saving installation space. Therefore, the sealing lip does not primarily expand radially but is compressed axially, and the spring sections are, so to speak, folded together axially, thereby limiting the radial expansion of the sealing lip.

[0032] The massive section suitably has a thickness in the range 4 mm to 5 mm, the thickness preferably being measured in the cross-section and in the radial direction, i.e. perpendicular to the longitudinal axis.

[0033] The spring section preferably has a thickness in the range of 1.5 mm to 3 mm, the thickness preferably being measured in the cross-sectional and radial direction, i.e. perpendicular to the longitudinal axis.

[0034] In one useful embodiment, the grommet is configured to be mounted in or on a wall and has at least one socket or hole, particularly as part of the inner body, for passing a cable, line, or conduit through the wall. Alternatively, the socket or hole can be used to embed other functional components in the grommet. The socket or hole of the grommet does not necessarily have to be concentric with the sealing lip, but can also be arranged non-concentrically and extend parallel to and at a radial distance from the longitudinal axis.

[0035] Preferably, the sealing lip, the sealing lip and inner body, or the entire grommet, are made from an elastic material. Suitably, the elastic material is a plastic, preferably EPDM, such that at least the sealing lip is made from EPDM (i.e., ethylene-propylene-diene rubber). Preferably, the inner body is also made from EPDM and, moreover, is advantageously made integrally, i.e., monolithically, with the sealing lip. Overall, the grommet is preferably made at least primarily from rubber and / or thermoplastic. Some grommet embodiments may include one or more inserts (see below), which are not necessarily made from an elastic material but are rather preferably made from a rigid material, such as PP, PE, ABS, metal, or other material.

[0036] Also advantageous is an embodiment in which the grommet has an insert (first insert) for fixing the grommet to the mounting surface, i.e., in or on the wall, so that the spring section remains compressed after assembly, thereby pretensioning it. For this purpose, the insert preferably includes multiple fixing elements. In a particularly preferred embodiment, the fixing elements are configured as clips for fastening the grommet on or within the wall. The inserts are preferably made of a material that is more rigid than the sealing lip and, if necessary, the inner body. Each clip has a head that forms an undercut, so that the entire clip is formed as a barb. When the grommet is mounted in or on the wall, the insert is pushed through a hole from one side of the wall, and after the head is pushed through, it springs radially outward on the other side, engaging and hooking the grommet to the wall. The sealing lip itself is not pushed through the hole in the wall, but is simply pressed and compressed to one side. In the assembled state, one sealing lip and one or more heads on the other side are positioned on opposite sides of the wall, thereby clamping the wall accordingly. The spring action of the compressed spring section ensures that the grommet is attached particularly firmly to the wall.

[0037] In an advantageous embodiment, the sealing lip comprises a number of bulges (different from the bulges of the spring section) for accommodating a corresponding number of fastening elements of the insert described above. Apart from the bulges, the sealing lip is preferably rotationally symmetrical about its longitudinal axis. The number of bulges is, for example, three, although other numbers, such as two, four or more, are in principle also suitable. The bulges are preferably evenly distributed around the circumference of the sealing lip. Each bulge provides a small volume inside the grommet for accommodating a fastening element, such as the aforementioned clip or part thereof, preferably at least in the uncompressed state. In a preferred embodiment, the fastening element is released from the bulge during installation and engages with the opposite wall of the sealing lip, so that in the compressed state the fastening element is no longer present in the bulge.

[0038] In an advantageous embodiment, said insert is particularly rigid compared to the sealing lip and serves to mechanically stabilize the grommet, a function which can also be achieved by a corresponding insert apart from the above-mentioned fixing function.

[0039] In a preferred embodiment, the grommet has an insert (second insert) for restricting the air volume inside the grommet and thereby improving its acoustic behavior. Such an insert is preferably plate-shaped and extends perpendicular to the longitudinal axis. Preferably, the insert surrounds any sockets or holes in the inner body. The insert is preferably separate from the aforementioned inserts for fixation and / or mechanical stability, but they may be the same.

[0040] One particular advantage is that the special shape of the sealing lip primarily causes axial deformation of the sealing lip, essentially independent of the direction of the mechanical load. At the same time, the special shape of the sealing lip also limits radial deformation. This advantageously minimizes the expansion or divergence of the grommet on the mounting surface when absorbing mechanical loads, for example, due to movement of a cable, line, or conduit held by the grommet. When the grommet is pressed against the mounting surface under mechanical load, excessive radial outward expansion of the grommet on the mounting surface is prevented. Depending on the mechanical load, the spring section advantageously compresses (which may include the aforementioned radial bulge) or decompresses like a spring, thereby absorbing particularly strong translational movements of the grommet while maintaining an optimal seal. The sealing effect between the sealing lip and the mounting surface is thus maintained despite severe boundary conditions.

[0041] A further advantage is that particularly small dimensions, in particular thicknesses, are possible, in particular for the grommet, in particular for the sealing lip, for example as already mentioned above, which saves material.

[0042] In particular, in embodiments with a massive section, the contact area between the sealing lip and the mounting surface is increased, which has the further advantage of resulting in a better seal. Since the massive section is particularly thicker or more voluminous than the spring section, the massive section also has a corresponding mass, e.g., 10 g to 15 g, which then further contributes to the seal, provided that the sealing lip is positioned on the mounting surface from above, i.e., supported by gravity, depending on the orientation of the grommet relative to gravity in the installed state. However, in the case of a grommet between the engine compartment and the interior of the vehicle, the longitudinal direction usually extends parallel to the roadway and perpendicular to gravity.

[0043] A further advantage, as already mentioned several times, is that the installation space required, especially for grommets, can be minimized. Vehicle manufacturers always specify a limited area on the mounting surface, e.g., the surface of a metal sheet, so that the grommets do not protrude. The special shape of the sealing lip described here ensures a particularly high level of sealing in a particularly small installation space.

[0044] Another advantage is that the sealing lip, especially the end section, is in direct contact with the mounting surface, making it particularly leak-tight against media, especially water and sound.

[0045] Another advantage is that the grommet is easier to assemble, especially since less force is required during assembly compared to grommets that only have a tapered sealing lip, which reduces fatigue for the person assembling the grommet.

[0046] The problem is also solved, in particular, by the use of the grommet described above for sealing against a mounting surface. Furthermore, the problem is also solved, in particular, by a method for manufacturing the grommet described above and a method for installing the grommet described above. The comments regarding the grommet also apply, as appropriate, to the uses and the two methods.

[0047] Examples of embodiments of the invention will now be described in more detail with reference to the drawings, which include several figures and are generally illustrated as follows: [Brief explanation of the drawings]

[0048] [Figure 1] A perspective view of the grommet from behind. [Figure 2] FIG. 2 is a front view of the grommet of FIG. 1. [Figure 3] Rear view of the grommet in Figure 1. [Figure 4] FIG. 2 is a side view of the grommet of FIG. 1. [Figure 5] Cross-sectional view of the grommet in Figure 1. [Figure 6] 2 is a cross-sectional perspective view of the sealing lip of the grommet of FIG. 1; [Figure 7] 2 is a partial cross-sectional view of the grommet of FIG. 1 in an uncompressed state. [Figure 8] 2 is a partial cross-sectional view of the grommet of FIG. 1 in a compressed state. [Figure 9] 2 is an alternative embodiment of the grommet of FIG. 1 (cross-section and uncompressed state). [Figure 10] Figure 9 Grommet in compressed state. [Figure 11] 2 is another alternative embodiment of the grommet of FIG. 1 (cross-section and uncompressed state). [Figure 12] 2 is another alternative embodiment of the grommet of FIG. 1 (cross-section and uncompressed state). [Figure 13] Figure 12 Grommet in compressed state. DETAILED DESCRIPTION OF THE INVENTION

[0049] The figures show several possible embodiments of the grommet 2 with a special sealing lip 4. The sealing lip 4 is designed to be compressible in a unique way during assembly and, if necessary, even when subjected to mechanical loads after assembly. The special sealing lip 4 ensures that the grommet 2 is highly leak-tight, while still being flexible and requiring minimal installation space.

[0050] The sealing lip 4 of the grommet 2 is used to establish a sealing contact with the mounting surface 6, e.g., the side of a wall 8, e.g., a metal plate. In this example, the sealing lip 4 extends annularly around a longitudinal axis L that extends in the axial direction A and is perpendicular to the radial direction R. The sealing lip 4 has a spring section 10 that is configured so that the sealing lip 4 can be compressed, particularly during assembly, i.e., installation, of the grommet 2 in or on the wall 8. Due to the spring section 10, the sealing lip 4 is also referred to as a "spring sealing lip." Due to the spring section 10, the sealing lip 4 is not designed as a simple ramp, but has a more complex shape, as shown, for example, in Figures 5 to 13, and in particular in the close-up view of Figure 6.

[0051] The sealing lip 4 shown here is, to a first approximation, conical or bell-shaped, as can be seen in the side view of FIG. 4, the cross-sectional views of FIGS. 5 and 7-13, and again in the detailed view of FIG. 6. In the embodiment shown here, the sealing lip 4 is rotationally symmetric about the longitudinal axis L; in FIGS. 12 and 13, this symmetry is broken only by multiple bulges 12. The grommet 2 optionally includes an inner body 14 to which the sealing lip 4 is radially outwardly connected, thereby completely surrounding the inner body 14. In this embodiment, the inner body 14 functions to perform additional functions of the grommet 2 besides sealing, such as for sealing and retaining a cable, line, or conduit 16 (see, e.g., FIG. 5) via a socket or hole 18 as part of the inner body 14. The inner body 14 can have any number of sockets or holes 18; two sockets or holes 18 are visible in FIGS. 1, 2, 3, and 5.

[0052] The grommet 2, and more specifically its sealing lip 4, has a compressed or loaded state, as shown in Figures 8, 10 and 13, and a non-compressed or unloaded state, as shown in Figures 7, 9, 11 and 12. During assembly of the grommet 2, the grommet 2 is constantly compressed and remains compressed in the assembled state, so that the sealing lip 4 is permanently pressed against the mounting surface 6 and exerts a sealing effect. The sealing lip 4 is thus, as it were, pretensioned by the spring section 10 in the assembled state, as shown, for example, in Figures 8, 10 and 13. The compression of the sealing lip 4 relative to the grommet 2 in Figure 11 is essentially the same as in Figure 10.

[0053] A possible embodiment of the spring section 10 is shown in detail in the cross-sectional view of FIG. 6, but its special shape and variations are also clearly shown in the remaining figures. The spring section 10 is circumferential and extends annularly around the longitudinal axis L and annularly around the inner body 14. The spring section 10 performs a spring function in particular in the axial direction A, so that the sealing lip 4 can be compressed at least in the axial direction A. The spring section 10 is therefore designed as a spring overall and acts like a spring, in particular when viewed in a cross-section along the longitudinal axis L as shown in FIGS. 5 to 13. The cross-section along the longitudinal axis L is spanned on the one hand by the radial direction R and on the other by the axial direction A, and originates from a cross-sectional plane in which the longitudinal axis L lies.

[0054] The special shape of the sealing lip 4 is based on the observation that the grommet 2 can, in principle, be designed with a circumferential, inclined sealing lip that protrudes at a specific angle from the inner body 14 of the grommet 2 and sealingly rests against the mounting surface 6. When mechanical loads are applied in the axial direction A, especially during assembly, the inclined sealing lip will widen or diverge and open further, while the actual inclined sealing lip shape remains largely intact. However, this significantly increases the diameter of the grommet 2 and occupies a corresponding amount of installation space. The same applies to mechanical loads in the axial direction A in the assembled state. Furthermore, such a grommet 2 may not be able to adequately absorb mechanical loads in the radial direction R, which could result in it being lifted off the mounting surface 6 and losing its sealing effect.

[0055] In contrast to this, the spring section 10 described herein advantageously allows for compression of the sealing lip 4 when the sealing lip 4 is subjected to a mechanical load, without requiring additional installation space on the mounting surface 6. Instead, the spring section 10 is compressed, particularly in the axial direction A, so that the sealing lip 4 on the mounting surface 6 absorbs the mechanical load without, at least not appreciably, expanding, as is evident when comparing Figures 7 and 8 with each other, and when comparing Figures 9 and 10 and Figures 12 and 13.

[0056] In the embodiment shown, the sealing lip 4 comprises an end section 20 that is affixed to the spring section 10 and that directly contacts the mounting surface 6 after installation. The sealing lip 4 is connected to the inner body 14 on the outside in the radial direction R, and the spring section 10 pivotally connects the inner body 14 to the end section 20. The spring section 10 therefore functions as a link or hinge that collapses in compression and bulges radially outward as a whole.

[0057] In all embodiments shown herein, the sealing lip 4 is rounded at its end, and more specifically, the end section 20 is rounded to facilitate contact with the mounting surface 6. The end section 20 is rounded so that the sealing lip 4, when mounted on the mounting surface 6, undergoes a rolling and / or sliding movement in the radial direction R, thereby deforming the spring section 10 and compressing the sealing lip 4 in the axial direction A. The rolling and / or sliding movement of the sealing lip 4, and specifically of its end section 20, is inward in the radial direction R, thereby reducing the installation space on the mounting surface 6.

[0058] End section 20, when viewed in cross section, generally has an outward-facing (i.e., toward the outside and toward the mounting surface) surface that is rounded or convex as seen in all figures, and an inward-facing (i.e., toward the longitudinal axis L and the interior of grommet 2) surface that is flat or concave (not shown) as in Figures 12 and 13, but may be rounded or convex as in the other figures. During installation, the outward-facing surface engages mounting surface 6 and rolls and / or slides across said mounting surface 6 upon compression, causing end section 20 to roll and / or slide inward and the inward-facing section to pivot away from mounting surface 6 (similar to a shoveling action). In the embodiment shown in Figures 5-11, sealing lip 4 is rounded by having a spherical or drop-shaped end when viewed in cross section.

[0059] In this example, the spring section 10 is configured so that the sealing lip 4 expands (i.e., flares) in the axial direction A like a cone or funnel in the uncompressed (i.e., unloaded) state and expands in the radial direction R in the compressed (i.e., loaded) state. More specifically, the spring section 10 assumes a curved shape when loaded, as shown in FIGS. 8, 10, and 13. As is evident from FIGS. 7, 9, 11, and 12, the spring section 10 shown here does not expand in the uncompressed state. Thus, the spring effect is achieved precisely by the fact that the spring section 10 expands in the radial direction R when loaded, thereby compressing the sealing lip 4 in the axial direction A. The end section 20 of the sealing lip 4 that directly contacts the mounting surface 6 after installation does not expand when loaded, and therefore does not require more installation space on the mounting surface 6. Instead, the spring section 10 arches so that the end section 20 remains in a substantially unchanged position on the mounting surface 6. In the uncompressed state, the sealing lip 4 forms an angle W with the longitudinal axis L, which in the embodiment shown is in the range of 2° to 30°.

[0060] The sealing lip 4 in this embodiment has an inner wall 21 facing generally in the direction of the longitudinal axis L and an outer wall 23 facing generally in the opposite direction. When viewed in cross section, the inner wall 21 has a contour that follows the contour of the outer wall 23. As can be seen, the sealing lip 4 has a thickness D measured in the radial direction R in an uncompressed state.

[0061] The curved shape is such that the inner wall 21 and the outer wall 23 of the spring section 10 are curved in the same direction. In other words, the spring section 10 bulges in only one direction and is therefore, so to speak, folded. This is the opposite of squeezing, which does not occur here, or at least is not the primary mechanism for compressing the sealing lip 4. Instead, the spring section 10 is, so to speak, folded to create a bulge. In other words again, the inner wall 21 and the outer wall 23 of the spring section 10 move in the same direction (both radially outward or both radially inward) upon compression.

[0062] The spring section 10 may bulge outward in the radial direction R, as in the embodiment shown here (and thus be convex when compressed), or may bulge inward (and thus be concave when compressed), as in alternatives not explicitly shown here. In other words, the spring section 10 is configured to bulge outward when the sealing lip 4 is attached, and thus generally when compressed. This also allows more volume to be available inside the grommet 2 than would be the case without the bulge or if the spring section 10 were bulging inward, improving acoustic behavior.

[0063] The illustrated spring section 10 is spring-like in that it has multiple segments 22 (also called joints) that connect to one another, making the spring section 10 as a whole articulated or hinged. The spring section 10 preferably has two (FIGS. 9-13), three (as in FIGS. 5-8), or four (not shown) segments 22, although other numbers are suitable depending on the application. One of the segments 22 is the first segment 22 and is connected to the inner body 14. Another segment 22 is the second segment 22 and is connected to the first segment 22. The second segment 22 may be the last segment 22 for contacting the mounting surface 6 or may be connected to a third segment 22 or end section 20, as previously described, thereby linking the first segment 22 and the third segment 22 or end section 20. Additional segments 22 may be added as needed. The two segments 22 are connected to one another so as to be pivotable relative to one another, thereby enabling the described inflation of the spring section 10. The bulging is achieved primarily by the rotation of the segments 22, and less by the deformation of the individual segments 22 themselves.

[0064] In the illustrated embodiment, some of the segments 22 are pivotally connected to one another at connection points 25, such that bends, creases, steps, shoulders, notches, grooves, or the like are formed at said connection points 25 to facilitate pivoting. In all of the illustrated embodiments, a step or shoulder is formed at each connection point 25. Alternatively, or additionally (as shown here), the section of spring 10 at connection point 25 has a reduced thickness D to facilitate pivoting, i.e., thickness D is reduced at connection point 25 compared to other thicknesses D at segments 22. In the embodiment shown, this reduction in thickness D is achieved by steps or shoulders configured such that the contour on inner wall 21 is displaced or offset in the axial direction A relative to the contour of outer wall 23, thereby achieving a staggered arrangement, where the inner portion of the step or shoulder on inner wall 21 is shifted in the axial direction A relative to the outer portion of said step or shoulder on outer wall 23 (however, such displacement or offset in the axial direction A is not strictly necessary to achieve a reduced thickness in the radial direction R).

[0065] In the exemplary embodiment of Figures 7-13, the spring section 10, at least in the uncompressed state, has a stepped shape when viewed in cross section along the longitudinal axis L. In the compressed state shown in Figures 8, 10 and 13, the segments 22 bulge outwardly together, as already described above.

[0066] In the embodiment shown, the end section 20 is configured as a massive section, which is thicker than the spring section 10 when measured in the radial direction R. The sealing lip 4 is therefore thickened at the end, and the massive section has a greater thickness D than the spring section 10, the thickness D being measured in cross section and in the radial direction R. The massive section together with the spring section 10 forms a massive-spring system with advantageous mechanical properties.

[0067] Because the massive section is thicker than the spring section 10, when a load is applied, the spring section 10 primarily deforms, specifically compresses, but the massive section does not deform significantly, thereby maintaining the sealing effect of the grommet 2. In accordance with the different functions of the two sections in the deformation of the sealing lip 4, the spring section 10 is also referred to as the "first deformation zone," and the massive section is also referred to as the "second deformation zone." Both deformation zones are indicated by respective rectangular frames in Figures 7 and 8, and their respective functions, i.e., functions related to axial deformation AD and radial deformation RD, are indicated by corresponding arrows. The massive section does not necessarily deform itself, but it significantly influences the deformation of the spring section 10. In particular, in this design, the axial deformation AD of the sealing lip 4 takes precedence over the radial deformation RD, limiting the radial deformation RD and, therefore, the radial protrusion. Therefore, the sealing lip 4 does not expand predominantly in the radial direction R but is compressed in the axial direction A, and the spring sections 10 are folded together in the axial direction A, as it were, which limits the expansion of the sealing lip 4 in the radial direction R.

[0068] As previously indicated, the grommet 2 shown here has an inner body 14 to which the sealing lip 4 is connected radially outwardly in the direction R. The spring section 10 pivotally connects the inner body 14 to the solid section and functions as a link or hinge that collapses in compression.

[0069] The sealing lip 4 is made of, for example, EPDM (i.e., ethylene-propylene-diene rubber). Optionally, the inner body 14 is also made of EPDM. Furthermore (as shown here), the inner body 14 and the sealing lip 4 are made integrally, i.e., monolithically.

[0070] The grommet 2 shown here also includes an insert 26 (first insert) for securing each grommet 2 in or on the wall 8 in such a way that the spring section 10 remains compressed and thus pretensioned after assembly. To this end, the insert 26 includes a number of clips 28 for fastening the grommet 2 on or within the wall 8. The insert 26 is made of a material that is more rigid than the sealing lip 4. Each clip 28 has a head 30 that forms an undercut, so that the clip 28 as a whole is formed as a barb. When the grommet 2 is installed in or on the wall 8, the insert 26 is pushed through a hole from one side of the wall 8, and after the head 30 is pushed through, it rebounds radially outward on the other side and engages, thereby hooking the grommet 2 to the wall 8. The sealing lip 4 itself is not pushed through a hole in the wall 8, but is simply pressed against one side and compressed. In the assembled state, the sealing lip 4 on the one hand and the head 30 on the other hand are placed on opposite sides of the wall 8, which is clamped accordingly. Due to the spring action of the compressed spring section 10, the grommet 2 is attached particularly firmly to the wall.

[0071] 12 and 13, the sealing lip 4 is provided with a number of bulges 12 which, at least in the uncompressed state shown in Fig. 12, accommodate a corresponding number of fixing elements, here clips 28. In Fig. 13, the fixing elements are released from the bulges 12 upon installation and engage the opposite wall 8 of the sealing lip 4.

[0072] Here, said insert 26 has a higher rigidity than the sealing lip 4 and also serves to mechanically stabilize the grommet 2. However, such a function can also be achieved by a corresponding insert, separate from the above-mentioned fixing function.

[0073] Additionally, the illustrated grommet 2 optionally includes another insert 32 (second insert) to limit the air volume within the grommet 2, thereby improving acoustic performance. Such an insert 32 can be seen in Figure 3. The insert 32 is plate-shaped, extends perpendicular to the longitudinal axis L, and surrounds any sockets or holes 18 in the inner body 14.

[0074] Each of the inserts 26, 32 is purely optional and the design of each may be entirely different from that shown here. [Explanation of symbols]

[0075] 2 grommets 4 Sealing Lip 6 Mounting surface 8. Wall 10 Spring Section 12 Bulge 14 Inner body 16 Cables, lines or conduits 18 Socket or hole 20 End sections (especially blocky sections) 21 Inner wall 22 segments 23 Exterior Wall 25 connection points 26 Insert (1st Insert) 28 clips 30 head 32 Insert (Second Insert) A axis direction AD Axial deformation D Thickness L Longitudinal direction R Radial direction RD Radial deformation W angle

Claims

1. It has a sealing lip (4), - said sealing lip (4) extends around a longitudinal axis (L) extending in the axial direction (A); - said sealing lip (4) has a spring section (10) configured so that said sealing lip (4) is compressible; The spring section (10) is spring-like and has a plurality of segments (22) that are connected to one another, thereby making the spring section (10) as a whole articulated or hinged; The spring section (10) is configured to bulge outward when compressed. Grommet (2).

2. the spring section (10) performs a spring function, whereby the sealing lip (4) is compressible at least in the axial direction (A); A grommet (2) according to claim 1.

3. the spring section (10) is configured to allow compression of the sealing lip (4) so ​​that when the sealing lip (4) is subjected to a mechanical load, no additional installation space is required on the mounting surface (6), but instead the spring section (10) is compressed, thus absorbing the mechanical load without expanding the sealing lip (4) on the mounting surface (6). A grommet (2) according to claim 1 or 2.

4. The sealing lip (4) is connected to an inner body (14) on the radially outer side (R), the sealing lip (4) comprises an end section (20) attached to the spring section (10) and in direct contact with the mounting surface (6) after mounting; The spring section (10) pivotally connects the inner body (14) to the end section (20). A grommet (2) according to claim 1 or 2.

5. The sealing lip (4) is configured such that the end section (20) does not expand during loading and therefore does not require more installation space on the mounting surface (6), but instead the spring section (10) arcs so that the end section (20) remains in an unchanged position on the mounting surface (6) or moves inward on the mounting surface (6). A grommet (2) according to claim 4.

6. the end section (20) is rounded so as to undergo a rolling and / or sliding movement in the radial direction (R) when attached to the mounting surface (6), thereby deforming the spring section (10) and compressing the sealing lip (4) in the axial direction (A); A grommet (2) according to claim 4.

7. The spring section (10) is configured such that the sealing lip (4) expands in the axial direction (A) in an uncompressed state and bulges outward in the radial direction (R) in a compressed state. A grommet (2) according to claim 1 or 2.

8. The spring section (10) is configured to bulge outward so as to maintain or increase the volume within the grommet (2), the volume being defined as the volume enclosed between the grommet (2) and the mounting surface (6). A grommet (2) according to claim 7.

9. the sealing lip (4) extends at an angle (W) relative to the longitudinal axis (L), the angle (W) being in the range of 2° to 30° in an uncompressed state; A grommet (2) according to claim 1 or 2.

10. At least two of the segments (22) are pivotally connected to one another at a connection point such that a bend, crease, step, shoulder, notch, or groove is formed at the connection point to facilitate pivoting; and / or At least two of the segments (22) are pivotally connected to one another at their connection points such that the spring section (10) has a reduced thickness as measured in the radial direction (R) at the connection points to facilitate pivoting. A grommet (2) according to claim 1 or 2.

11. the spring section (10) has a stepped or serpentine shape when viewed in cross section along the longitudinal axis (L); A grommet (2) according to claim 1 or 2.

12. the sealing lip (4) comprises an end section (20), the end section (20) being configured as a solid section and being thicker than the spring section (10) when measured in the radial direction (R); A grommet (2) according to claim 1 or 2.

13. 13. The grommet (2) according to claim 12, wherein the massive section is spherical or drop-shaped in cross section along the longitudinal axis (L).

14. The massive section has a thickness (D) in the range of 4 mm to 5 mm; A grommet (2) according to claim 12.

15. The spring section (10) has a thickness (D) in the range of 1.5 mm to 3 mm. A grommet (2) according to claim 1 or 2.

16. configured to be mounted on a wall (8); said wall (8) having at least one socket or hole (18) for passing a cable, line or conduit (16); A grommet (2) according to claim 1 or 2.

17. The sealing lip (4) is made of EPDM. A grommet (2) according to claim 1 or 2.

18. the sealing lip (4) is rotationally symmetrical about the longitudinal axis (L); A grommet (2) according to claim 1 or 2.

19. Having a sealing lip (4), - said sealing lip (4) extends around a longitudinal axis (L) extending in the axial direction (A); - said sealing lip (4) has a spring section (10) configured so that said sealing lip (4) is compressible; having inserts (26) for fixing in or on the wall (8) so that the spring sections (10) remain compressed after assembly and are therefore pretensioned, the sealing lip (4) comprises a number of bulges to accommodate a corresponding number of fixing elements of the insert; Grommet (2).

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